@mixin flex {
  display: flex;
  display: -webkit-flex;
}

@mixin flex-v {
  @include flex;
  flex-direction: column;
}

@mixin flex-v-ac {
  @include flex-v;
  align-items: center;
}

@mixin flex-h {
  @include flex;
  flex-direction: row;
}

@mixin flex-h-ac {
  @include flex-h;
  align-items: center;
}